When I did the work on the query engine described above I used an OpVisitor implementation in modifyOp to rewrite the query. It should be possible to implement the optimization there, but I don't know that it is the best place.
Claude On Wed, Aug 28, 2013 at 5:19 PM, Diogo FC Patrao <[email protected]>wrote: > Hi Claude > > I meant the first option, optimize queries to run at federated > environments. Although I'm working on a query "federator" as well, and am > also interested in similar projects as well. > > Thanks > > -- > diogo patrão > > > > > On Wed, Aug 28, 2013 at 12:50 PM, Claude Warren <[email protected]> wrote: > > > I did some work on query planning for federated queries when I worked for > > DERI. (http://deri.ie). However, that work may have been a bit more > > complex than you are considering as we had some sources for vocabulary > > equivalence and were attempting to handle that at the same time. > > > > When you say a query planner for federated queries, are you looking to > > optimise queries that contain federated queries, or attempting to build a > > federated query from a non-federated one? > > > > Claude > > > > > > On Wed, Aug 28, 2013 at 1:54 PM, Diogo FC Patrao <[email protected] > > >wrote: > > > > > Hello > > > > > > I was thinking about writing a query planner for federated queries. > > AFAIK, > > > there's no such thing on ARQ, and couldn't find any third-party libs > for > > > that. > > > > > > So my questions are: > > > > > > 1) do you know of any open source projects out there that deals with > it? > > > I'm willing to contribute. > > > > > > 2) If there is no such project, is a Transformer the right place to go > > for > > > it? I thought about extending TransformerCopy to reorder OpJoins to > solve > > > first those with smaller costs. > > > > > > Thanks! > > > > > > > > > -- > > > diogo patrão > > > > > > > > > > > -- > > I like: Like Like - The likeliest place on the web< > > http://like-like.xenei.com> > > Identity: https://www.identify.nu/[email protected] > > LinkedIn: http://www.linkedin.com/in/claudewarren > > > -- I like: Like Like - The likeliest place on the web<http://like-like.xenei.com> Identity: https://www.identify.nu/[email protected] LinkedIn: http://www.linkedin.com/in/claudewarren
